The building blocks of MACC are a set of components with specific functions that are grouped into four clusters.

The Input Data cluster acquires the satellite and in-situ observations and carries out preparatory processing of them. It also provides improved estimates of surface emissions of key species, with a particular emphasis on the highly variable emissions from fires.

The primary Global and Regional clusters operate and refine processing systems that include not only the data assimilation and modelling elements that provide the basic monitoring and forecasting products, but also the elements that provide estimates of climate forcing, inferred corrections to the modelled sources and sinks, and derived products such as UV radiation and resources for solar power generation.

An Outreach cluster provides the interface to downstream-service providers and other users, runs the service-chain test cases and supports the development of policy for the control of atmospheric pollution.